AddIdentity() fails “InvalidOperationException: Scheme already exists: Identity.Application”

Question

I\'m trying to add facebook login to my .NET Core 2.1 site

I\'m following this , guide and more specific, this (for facebook login)

After have adding the lines

Answer 1

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I had the same issue, I was registering services in two different files in the same time: Startup.cs and IdentityHostingStartup.cs files.

What I did?

I sepeprated registering the services in both files as following:

IdentityHostingStartup.cs

I only registered Identity DB Context in this file:
//lets register identity db context builder.ConfigureServices((context, services) => { services.AddDbContext(options => options.UseSqlServer( context.Configuration.GetConnectionString("IdentityDBConnection"), x => x.MigrationsAssembly("WebApplication1") ) );

Startup.cs

In this file I registered DefaultIdentity, Roles and EntityFrameworkstores
//I registered the DefaultIdentity, the Roles and the EntityFrameworkstores services.AddDefaultIdentity(options => options.SignIn.RequireConfirmedAccount = true) .AddRoles().AddEntityFrameworkStores();